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McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved. 9-1 BUSINESS DRIVEN TECHNOLOGY Business Plug-In B9 Systems Development.

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Presentation on theme: "McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved. 9-1 BUSINESS DRIVEN TECHNOLOGY Business Plug-In B9 Systems Development."— Presentation transcript:

1 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved. 9-1 BUSINESS DRIVEN TECHNOLOGY Business Plug-In B9 Systems Development

2 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved. 9-2 LEARNING OUTCOMES 1.Summarize the activities associated with the planning phase in the SDLC 2.Summarize the activities associated with the analysis phase in the SDLC 3.Summarize the activities associated with the design phase in the SDLC 4.Summarize the activities associated with the development phase in the SDLC

3 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved. 9-3 LEARNING OUTCOMES 5.Summarize the activities associated with the testing phase in the SDLC 6.Summarize the activities associated with the implementation phase in the SDLC 7.Summarize the activities associated with the maintenance phase in the SDLC

4 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved. 9-4 Introduction Large, complex IT systems take teams of architects, analysts, developers, testers, and users many years to create The systems development life cycle is the foundation for many systems development methodologies such as RAD and agile – Systems development life cycle – the overall process for developing information systems from planning and analysis through implementation and maintenance

5 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved. 9-5 Introduction 9-5

6 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved. 9-6 Systems Development Life Cycle - PHASE 1: PLANNING Planning phase – involves establishing a high- level plan of the intended project and determining project goals Primary planning activities include 1.Identify and select the system for development 2.Assess project feasibility 3.Develop the project plan

7 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved. 9-7 PLANNING 1: Identify and Select the System for Development Organizations use different forms of evaluation criteria to determine which systems to develop – Critical success factor (CSF) – a factor that is critical to an organization’s success

8 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved. 9-8 PLANNING 2: Assess Project Feasibility Feasibility study – determines if the proposed solution is feasible and achievable from a financial, technical, and organizational standpoint Different types of feasibility studies – Economic feasibility study – Operational feasibility study – Technical feasibility study – Schedule feasibility study – Legal and contractual feasibility study

9 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved. 9-9 PLANNING 3: Develop the Project Plan Developing the project plan is a difficult and important activity The project plan is the guiding force behind on- time delivery of a complete and successful system Continuous updating of the project plan must be performed during every subsequent phase during the SDLC

10 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved Systems Development Life Cycle – PHASE 2: ANALYSIS Analysis phase – involves analyzing end-user business requirements and refining project goals into defined functions and operations of the intended system Primary analysis activities include 1.Gather business requirements 2.Create process diagrams 3.Perform a buy vs. build analysis

11 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved ANALYSIS 1: Gather Business Requirements Business requirements – the detailed set of business requests that the system must meet in order to be successful Different ways to gather business requirements – Joint application development (JAD) session – where employees meet to define or review the business requirements for the system – Interviews – Questionnaires – Observations – Review business documents

12 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved ANALYSIS 1: Gather Business Requirements The system users review the requirements definition document and determine if they will sign-off on the business requirements – Requirements definition document – contains the final set of business requirements, prioritized in order of business importance – Sign-off – the system users’ actual signatures indicating they approve all of the business requirements

13 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved ANALYSIS 2: Create Process Diagrams Process modeling – graphically representing the processes that capture, manipulate, store, and distribute information between a system and its environment Common process modeling diagrams include – Data flow diagram (DFD) – illustrates the movement of information between external entities and the processes and data stores within the system – Computer-aided software engineering (CASE) tools – automate systems analysis, design, and development

14 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved ANALYSIS 2: Create Process Diagrams Sample data flow diagram

15 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved ANALYSIS 3: Perform a Buy vs. Build Analysis An organization faces two primary choices when deciding to develop an information system 1. Buy the information system from a vendor – Commercial off-the shelf (COTS) – software package or solution that is purchased to support one or more business functions and information systems – SCM, CRM, and ERP solutions are typically COTS 2. Build the information system itself

16 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved ANALYSIS 3: Perform a Buy vs. Build Analysis Organizations must consider the following when making a buy vs. build decision: – Are there any currently available products that fit the organization’s needs? – Are there features that are not available and important enough to warrant the expense of in-house development? – Can the organization customize or modify an existing COTS to fit its needs? – Is there a justification to purchase or develop based on the cost of acquisition?

17 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved ANALYSIS 3: Perform a Buy vs. Build Analysis Three key factors an organization should also consider when contemplating the buy vs. build decision: 1.Time to market 2.Availability of corporate resources 3.Corporate core competencies

18 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved Systems Development Life Cycle – PHASE 3: DESIGN Design phase – involves describing the desired features and operations of the system including screen layouts, business rules, process diagrams, pseudo code, and other documentation Primary design activities include: 1.Design the IT infrastructure 2.Design system models

19 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved DESIGN 1: Design the IT Infrastructure Organizations need a solid IT infrastructure to support their IT systems IT infrastructure must meet the organization’s needs in terms of time, cost, technical feasibility, and flexibility

20 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved DESIGN 1: Design the IT Infrastructure Sample IT infrastructure

21 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved DESIGN 2: Design System Models Modeling – the activity of drawing a graphical representation of a design Different modeling types include: – Graphical user interface (GUI) – the interface to an information system – GUI screen design – the ability to model the information system screens using icons, buttons, menus, and submenus – Data models – a formal way to express data relationships to a database management system (DBMS) – Entity relationship diagram (ERD) – a technique for documenting the relationships between entities in a database

22 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved DESIGN 2: Design System Models Sample entity relationship diagram (ERD)

23 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved Systems Development Life Cycle – PHASE 4: DEVELOPMENT Development phase – involves taking all of the detailed design documents from the design phase and transforming them into the actual system Primary development activities include: 1.Develop the IT infrastructure 2.Develop the database and programs

24 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved DEVELOPMENT 1: Develop the IT Infrastructure The platform upon which the system will operate must be built prior to building the actual system In the development phase, the organization purchases and implements the required equipment to support the IT infrastructure

25 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved DEVELOPMENT 2: Develop the Database and Programs Once the IT infrastructure is built, the organization can begin to create the database and write the programs required for the system IT specialists perform the majority of the tasks associated with the development phase

26 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved Systems Development Life Cycle – PHASE 5: TESTING Testing phase – involves bringing all the project pieces together into a special testing environment to test for errors, bugs, and interoperability, in order to verify that the system meets all the business requirements defined in the analysis phase Primary testing activities include: 1.Write the test conditions 2.Perform the system testing

27 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved TESTING 1: Write the Test Conditions Test condition – the detailed steps the system must perform along with the expected results of each step

28 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved TESTING 2: Perform the System Testing Different types of testing: – Unit testing – tests each unit of code upon completion – Application (or system) testing – verifies that all units of code work together – Integration testing – exposes faults in the integration of software components or units – Backup and recovery testing – tests the ability of an application to be restarted after failure – Documentation testing – verifies instruction guides are helpful and accurate – User acceptance testing (UAT) – tests if a system satisfies its acceptance criteria

29 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved Systems Development Life Cycle – PHASE 6: IMPLEMENTATION Implementation phase – involves placing the system into production so users can begin to perform actual business operations with the system Primary implementation activities include: 1.Write detailed user documentation 2.Determine implementation method 3.Provide training for the system users

30 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved IMPLEMENTATION 1: Write Detailed User Documentation System users require user documentation that highlights how to use the system User documentation – highlights how to use the system

31 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved IMPLEMENTATION 2: Determine Implementation Method Four primary implementation methods 1.Parallel implementation 2.Plunge implementation 3.Pilot implementation 4.Phased implementation

32 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved IMPLEMENTATION 3: Provide Training for the System Users Organizations must provide training for system users Two most popular types of training include: – Online training – runs over the Internet or off a CD- ROM – Workshop training – set in a classroom-type environment and led by an instructor

33 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved Systems Development Life Cycle – PHASE 7: MAINTENANCE Maintenance phase – involves performing changes, corrections, additions, and upgrades to ensure the system continues to meet the business goals Primary maintenance activities include: 1.Build a help desk to support the system users 2.Perform system maintenance 3.Provide an environment to support system changes

34 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved MAINTENANCE 1: Build a Help Desk to Support the System Users Internal system users have a phone number for the help desk they call whenever they have issues or questions about the system – Help desk – a group of people who respond to internal system user questions Providing a help desk is an excellent way to provide comprehensive support for new system users

35 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved MAINTENANCE 2: Perform System Maintenance Maintenance – fixing or enhancing an information system Different types of maintenance include – Adaptive maintenance – Corrective maintenance – Perfective maintenance – Preventative maintenance

36 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved MAINTENANCE 3: PROVIDE AN ENVIRONMENT TO SUPPORT SYSTEM CHANGES An organization must modify its systems to support the business environment It typically accomplishes this through change management systems and change control boards – Change management system – a collection of procedures to document a change request and define the steps necessary to consider the change based on the expected impact of the change – Change control board (CCB) – responsible for approving or rejecting all change requests

37 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved Software Problems Are Business Problems Primary reasons for project failure include – Unclear or missing business requirements – Skipping SDLC phases – Failure to manage project scope Scope creep – occurs when the scope increases Feature creep – occurs when extra features are added – Failure to manage project plan – Changing technology

38 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved Software Problems Are Business Problems Find errors early: the later in the SDLC an error is found - the more expensive it is to fix

39 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved Closing Case One Disaster at Denver International Airport DIAs baggage system relied on 300 computers to route bags and 4,000 telecars to carry luggage across 21 miles of track Due to baggage system failures, DIA delayed its opening for 16 months, costing taxpayers roughly $1 million per day, which totaled around $500 million

40 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved Closing Case One Questions 1.One of the problems with DIA’s baggage system was inadequate testing. Describe the different types of tests DIA could have used to help ensure its baggage system’s success 2.Evaluate the different implementation approaches and choose the one that would have most significantly increased the chances of the project’s success 3.Explain the cost of finding errors and how more time spent in the analysis and design phase could have saved Colorado taxpayers hundreds of millions of dollars 4.Explain why BAE could not take an existing IT infrastructure and simply increase its scale and expect it to work

41 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved Closing Case Two Reducing Ambiguity in Business Requirements The number one reason projects fail is bad business requirements Business requirements are considered “bad” because of ambiguity or insufficient involvement of end users during analysis and design A requirement is unambiguous if it has the same interpretation for all parties

42 McGraw-Hill/Irwin © 2006 The McGraw-Hill Companies, Inc. All rights reserved Closing Case Two Questions 1.Why are ambiguous business requirements the leading cause of system development failures? 2.Explain why the words “and” and “or” tend to lead to ambiguous requirements 3.Research the Web and determine other reasons for “bad” business requirements 4.What is wrong with the following business requirement: “The system must support employee birthdays since every employee always has a birthday every year”


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